I use various plastic bags, emergency shelters, lightwight plastic ponchos, etc. to warm me while in camp. They break the wind and, when used in conjunction with sunlight or a campfire, the greenhouse effect can add a lot of warmth for the weight.

This untested version is my latest attempt to get the weight down on this item. I used an old 4/10 mill plastic drop cloth. A 9X12 piece is enough to make 4 of these. They are open at each end (think tube) and are 6 feet in circumferance and 4.5 feet tall. Weight came to .8 ounces and cost (purchased decades ago) was 5 cents each.

I bought some .33 ounce cuben to make this but the drop cloth was a little lighter and the cuben seemed like overkill. I think I could probably find some dry cleaner bags that might do the trick. This 4/10 mill plastic runs about .28 ounces per square yard and feels a lot like dry cleaner bags.

Looks interesting. We used to use garbage bags as cheap ponchos for the kids when we were camping - they work great (not breathable!) when head and armholes are cut. Looks like yours is similar but lighter and cheaper!

These weigh about 2 ounces each. The surface area is about the same as the .8 ounce one I posted so I'm guessing they might be made of something like 1 mil poly instead of .4 mil.

I've used them a lot and like them. I slit and tape the neckline to make it easier to get the hood over my bulbous head. I sometimes tape the arm holes shut to keep wind from blowing through them. I usuallly keep them tight to my body with a thin elastic cord that I wrap around my waist. Like the one I made, I only use them around camp or for rest stops while on the trail. Too fragile for much else.